UKY DENTAL COBRE: ORAL INFECTIONS AND HIV RECRUDESCENCE

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。采用高效抗逆转录病毒疗法（高效抗逆转录病毒疗法）大大改变了艾滋病毒的病程，延长了艾滋病毒感染者的存活率，改善了他们的生活质量。然而，目前可用的抗逆转录病毒治疗方案无法完全根除艾滋病毒感染。这主要是由于潜伏感染的CD4+ T细胞、巨噬细胞和其他宿主细胞(如：树突状细胞，肥大细胞)在急性艾滋病毒感染的早期阶段持续存在，半衰期极长。HIV-1在包括巨噬细胞在内的各种宿主免疫细胞中的持续存在构成了控制HIV-1感染的主要障碍。我们正在使用模型T细胞和巨噬细胞系统来评估口腔微生物挑战重新激活HIV的能力。我们最初的研究使用了BF24细胞系，这是一种转染了HIV LTR启动子驱动氯霉素乙酰转移酶（CAT）基因的人巨噬细胞。特异性目的1是检测这些细胞被口腔细菌（Pg, Sm, Cr, Fn）或声波攻击后的变化，以评估与种类，剂量和时间相关的HIV启动子激活的变化。我们还评估了多微生物挑战在这种激活中协同作用的能力。采用CAT酶联免疫吸附试验测定结果。各种口腔细菌和细菌声索激活HIV的能力存在差异，支持牙周炎患者口腔感染的特征可能不同程度地影响HIV的再激活。我们还注意到，与单独的任何一种细菌相比，多细菌对BF24细胞的攻击表现出加性再激活。特异性目标2侧重于宿主诱导分子重新激活HIV的能力。在这些研究中，我们用各种细菌声索挑战人类牙龈成纤维细胞（HGF）培养。然后用得到的上清液刺激BF24细胞中的HIV再激活。结果表明，HGF上清液对BF24细胞有一定的剂量和时间反应性。然而，这些反应明显少于细菌对巨噬细胞的直接刺激。最后，我们启动了一些HGF、巨噬细胞和细菌在同一环境中共培养的实验。初步结果表明，这些培养物中的因子可能实际上调节了激活HIV启动子的能力。因此，这些数据表明口腔细菌具有激活潜伏感染巨噬细胞中的HIV的能力。这种激活的程度有一定的特异性，对这些感染细胞的多细菌攻击可以增强HIV再激活。结果表明，慢性口腔感染对HIV感染患者的治疗成功存在风险。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The introduction of HAART regimens (Highly Active Antiretroviral Therapy) has significantly modified the course of HIV disease, with longer survival rates and improvement of life quality in HIV-infected individuals. However, complete eradication of HIV infection cannot be achieved with currently available antiretroviral regimens. This primarily results from the establishment of a pool of latently infected CD4+ T cells, macrophages, and other host cells (eg. dendritic cells, mast cells) during the very earliest stages of acute HIV infection that persists with an extremely long half-life. This persistence of HIV-1 within various host immune cells, including macrophages constitutes a major obstacle in the control of HIV-1 infection. We are using model T cell and macrophage systems to evaluate the capacity of the oral microbial challenges to reactivate HIV. Our initial studies have used the BF24 cell line, a human macrophage transfected with the HIV LTR promoter driving a chloramphenicol acetyltransferase (CAT) gene. Specific Aim 1 was to examine the alteration of these cells were challenged with oral bacteria (Pg, Sm, Cr, Fn) or sonicates to assess variations in HIV promoter activation related to species, dose, and time. We also evaluated the ability of a polymicrobial challenge to synergize in this activation. The outcome was measured using a CAT ELISA. Differences were noted in the ability of the various oral bacteria and bacterial sonicates to activate HIV, supporting that the characteristics of oral infection in periodontitis patients could variably impact reactivation of HIV. We also noted that a polybacterial challenge of the BF24 cells demonstrated an additive reactivation when compared to either bacterium alone. Specific Aim 2 focuses on the ability of host induced molecules to reactivate HIV. In these studies, we have challenged human gingival fibroblast (HGF) cultures with various bacterial sonicates. The resulting supernatants were then used to stimulate HIV reactivation in the BF24 cells. The findings indicated a dose and time responsiveness for the HGF supernatants to stimulate the BF24 cells. However, these reactions appeared substantially less that direct bacterial stimulation of the macrophages. Finally, we have initiated some co-culture experiments in which the HGF, macrophages and bacterial challenge take place in the same milieu. Initial results suggest that factors in these cultures may actually modulate the ability to activate the HIV promoter. Thus, the data demonstrate that oral bacteria have the capacity to activate HIV in latently infected macrophages. There appeared some specificity to the magnitude of this activation and a polybacterial challenge of these infected cells can enhance HIV reactivation. The results suggest chronic oral infections provide a risk to treatment success in HIV infected patients.